Mafiatale Sans x female reader (Possession)

Jealousy

This was a disaster; Chara and I were suppose to go to Mettaton's masquerade show and enjoy ourselves for once instead of being stuck at that empty mansion cleaning for Sans while him and Papyrus go about doing dangerous yet exciting things.

     The trip back to Snowdin was silent with a hint of frustration floating in the atmosphere. I sat next to Sans in the back of his car saying nothing to each other as he carelessly smoked inside and occasionally rolling down the window to let the smoke out. I was too afraid to look over at Sans who looked straight ahead with a blank stare, we would catch a glimpse of each other once in a while but never kept eye contact.

          I wasn't in the mood to talk to Chara. Afterall, she was the one that convinced me to leave the mansion to go have some fun.

     "what am i gonna to do with ya, (y/n)—?"

     I look over to Sans, wondering why he asked such a strange question. I didn't know what to say as he took my silence as a sign to continue.

     "i don't want to sound like my brother or anythin', but... of all the days ya chose to be rebellious, why the hell did ya pick today?"

     Sans was frustrated, but by the sound of exhaustion in his voice, it was apparent that he didn't have the energy to argue at the moment and just wanted a straight answer.

     "this was your little friend's idea, wasn't it?" He continued.

     "For the last time, her name is Chara. And what makes you think that this was her idea?" I answer. 

     "cause i know ya well enough that you wouldn't do something as risky as going to a theater packed with monsters who's soul intent was to find something more valuable than any amount of money in the Underground could offer." 

     Sans was right, he knew that I wouldn't have done something that potentially could've killed me and have my soul taken away by a power hungry demon goat. But I wanted to be free from that uninviting mansion; I was desperate for something new.

     Sans tosses out the remainder of his cigar through the window before as the opened window pushes the rest of the smoke out of the car.

     "doll, listen i— i don't understand why ya let that chara chick take control of ya again, she was bringin' ya pain the last time i saw ya with her."

     "She can't hurt me anymore... Gaster was able to fix that."

     "i don't care if wise head back home was able to fix ya, it's not right to let some other human's soul have their way with ya whenever they please!" Sans huffs.

     Sans' words hit me hard and a spark of realization came.

     "You're... jealous of Chara?" I say with a sly tone to my voice.

     "—of course not, why would i be grungy over some tiny soul!?"

     "I know you are." I whisper under my breath.

     Sans avoided my gaze by looking out the car window as I looked at his face that had a noticeable blush across his cheek bones.

     It was amusing to see Sans convey an emotion he doesn't rather show to me, if not to anyone at all.

     "Look, I know we recently agreed that we're now a couple, but why are you acting as if I've left you for some human soul?"

     "i would tell ya if she wasn't here."

     Sans' comment was enough to make me stop talking as I looked through the opposite window to avoid the bitter conversation.

     Do you think Sans will feel better if we show him that3 soul we found?